We discuss manifestly SL(2, C) x SU(4) and kappa -invariant superstring act
ion in an AHS(5) x S-5 background within the framework of the Green-Schwarz
formulation. The action is formulated in terms of 16 Poincare fermionic co
ordinates which through AdS/CFT correspondence should represent N = 4 SYM s
uperspace and 16 superconformal fermionic coordinates. The action is also m
anifestly invariant with respect to the usual N = 4 Poincare superalgebra t
ransformations. kappa -symmetry gauge fixing and the derivation of lightcon
e gauge action are simplified.